Jig



Am! 28, 1942. o. R. STRAWN 2,281,530

JIG

Filed July 19, 1959 6 Sheets-Sheet 1' OEVAL R. STRAWN, BY

April 1942, o. R. s'rRAwN JIG Filed July 19, 1939 6 Sheets-Sheet 2 fiWEA/TOR ORVAL R 5TRAWN, B

A TT'X A ril as, 1942. R, STR WN 2,281,530

JIG

Filed July 19, 1939 6 Sheets-Sheet 3 [/VVE/Y TOR. ORVAL R STRAW N,

ATT'X April 1942- 0. R; STRAWN I 21,281,530

JIG

Filed July 19, 1959 6 Sheets-Sheet 5 OEVAL. R.5TRAWN) Fig. 7 I I 7VLWi/Lh,

Ap ril 28, 1942. o. R. STRAWN 2,281,530

JIG

Filed July 19, 1939 6 Sheets-Sheet 6 [N VEN TOR ORVAL. E.ST AWN, BY

Patented Apr. 28, 1942 @rval R. Strawn, Colu mbus, Ohio, assignor to The Jefirey Manufacturing Company, a corporation of Ohio Application July 19, 1939, Serial No. 285,302

(Cl. 205l455) 3 Claims.

This invention relates to a jig particularly adapted to clean coal and separate refuses found in raw coal from the useable coal.

An object of the invention is to provide an improved compact construction in a Baum type jig.

Another object of the invention is to provide a jig having an improved type of control valve which is readily adjustable, to control the cycle of operation thereof.

A further object of the invention is to provide an improved air control valve particularly adapted for use in a jig.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings,

Fig. 1 is a side elevational view of a jig comprising my invention with parts shown in section;

Fig. 2 is a rear end elevational view of the jig;

Fig. 3 is a sectional elevational view taken on the line 3-3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a side elevaticnal view of one of the control valves comprising a feature of the invention;

Fig. 5 is an enlarged view showing control mechanism for an adjusting damper of the valve in Fig. 4;

Fig. 6 is an enlarged sectional view showing an adjustable damper of the valve of Fig. 4;

Fig. 7 is a plan view of the valve of Fig. 4;

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 4 looking in the direction of the arrows;

Fig. 9 is a sectional eievational view of the valve taken on the line 9-3 of Fig. 7 looking in the direction of the arrows;

Figs. 10 and 11 are enlarged sectional views showing details of adjusting means for slide plates of the control valve; and

Fig. 12 is a diagrammatical illustration of the four partitions in each cycle of operation of the control valve, by which their manner of adjustment is illustrated.

Referring particularly to Figs. ,1, 2 and 3 of the drawings, it will be seen that I have provided a jig of the Baum type having a main frame provided at its four corners with support feet 2| adapted to rest on a floor or other supporting structure of the coal cleaning plant.

Mounted on the main frame container 22 which is formed by tudinally extending upright side extend the full length of the jig a pair of longiwalls 23, which and which have 2a is a tank or I integral converging bottom walls 24, which meet to form a trough 25 in the bottom of the tank or container 22.

Between the upright side walls 23 is a longitudinally and upwardly extending partition 26.

As is well understood, the tank or container'22 receives the water or other jigging liquid and the cross sectional structure thereof, as clearly illustrated in Fig. 3 of the drawings, as well as the liquid, is formed into a U-shaped column in one leg of which, and between partition 26 and. one side wall 23, is a perforated plate or screen 2'1, having a plurality of re-enforcing bars 28 on the bottom thereof. Above the other leg of the water column there is formed an air chamber 29 between the partition 26 and another upright side wall 23, which chamber it also is provided by a top plate 30, which top plate 30 also constitutes the bottom plate of a plenum chamber 3| which extends the full length of the jig, the side walls of which are formed by the top of the aforementioned partition 26 and the top of one of the aforementioned side walls 23, and the top of which is formed by a longitudinally extend ing arched top plate 32. Air under pressure is delivered to plenum chamber 3! from a blower, compressor or the like by way of pipe St I.

It may be pointed out that I have illustrated a two compartment jig in the drawings, but it is evident that the number of compartments may be either increased or reduced. The two compartments of the jig are essentially the same in structure except for certain obvious differences, and one of the compartments is indicated generally by the reference character 33, the other by the reference character 3i. Except where a contrary fact is indicated, the two compartments 33 and 34 have the same construction.

The compartment 33 is provided with a feed chute 35 by which the raw coal to be treated is fed to the jig. Between the compartments 33 and 34 is a weir 36 over which the clean coal from compartment 33 flows to compartment 36. The clean coal from compartment 34 is discharged over weir 37 and down in chute 38 to an appropriate receiving means such as a sluiceway.

The herein described screens 21 associated with Adjacent the forward end of each screen 21 is a refuse discharge opening 44 which leads to the refuse ejecting mechanism 45, which is automatically controlled by a float operated automatic refuse discharge regulating mechanism 46, the structure of which substantially follows that described in the patent to John G. Attwood, No. 2,132,380, for a jig, dated October 11, 1938. It may be mentioned, however, that the operating pawls of this refuse discharge mechanism 46 are driven by a crank 41 which in turn is driven from an electric motor 48, as clearly illustrated in Figs. 1 and 2 of the drawings.

Furthermore, the pawl and ratchet mechanisms are mounted on one side of the container 22 and are preferably enclosed in protecting houses 49.

Each of the compartments 33 and 34 is preferably divided into a plurality of cells, and cells 50 and of compartment 34 are clearly seen by reference to Fig. l of the drawings. They are formed by a transverse partition 52 between the aforementioned partition 39 and the elevator casing 42.

The aforementioned perforated plate or screen 21 is adjustable by adjusting hang rods 53 so that its slope may be adjusted. To provide for this adjustment while preventing leakage between the cells 50 and 5|, screen 21 carries an overlapping downwardly projecting plate 54 in 3 overlapping relation with the partition 52. It may also be pointed out that the effective size of the opening 44 leading to the refuse ejecting mechanism 45 may be adjusted by a vertical adjustable slide plate 55 provided with adjustable hang rods 55 at opposite ends thereof and the effective height of the weir 37 may be adjusted by vertical adjustable weir plate 5! provided with adjustable hang rods 53 at opposite ends thereof.

This construction is substantially identical for I each of the compartments 33 and 34.

The bottom trough of each of the compartments 33 and 34, is provided with a screw conveyor 59 which conveys the hutch material to the left, as viewed in Fig. 1 of the drawings, and discharges it into the boot of the associated elevator casing or 42, where it is co-mingled with the refuse discharged thereinto by the associated refuse ejecting mechanism 45, and elevated by the elevating conveyor M or 43, by which it is discharged from the discharge opening thereof, that associated with casing 40 being seen at 60.

The elevating conveyor casings 4G and 42 are provided with manhole openings covered by appropriate cover plates 6| and 62, which of course provide access to the interior thereof. Access to the interior of each cell 5|! is. provided by a manhole opening having a cover plate 63, and once access is had to cell 59 access is then provided to cell 5| by a removable plate (54 associated with the partition 52. The boots at the bottom of casings M3 and 42 are provided with drain plugs '65 and 66, and the bottom of each compartment 33 and 34 is provided with a valve controlled drain pipe 61.

The main frame 20 also supports a walk 68 supported on one side of the tank 22 and adjacent the houses 49 associated with the refuse ejecting mechanisms 45. A handrail 69 is associated with the said walk 68.

From the above description it is evident that the complete jig illustrated in the drawings comprises two similar compartments, 33 and 34, each of which is provided with a pair of cells 58 and.

5! associated with a single perforated plate or screen 21, by which the coal to be treated is supported and over which it moves during the operation of the jig.

It is desired to provide individually adjustable controls for each of the cells 50 and 5|, of which there will of course be four in the two compartment jig illustrated. Therefore, each of said compartments 50 and 5| has an individual air chamber 29. Furthermore, each of said cells 50 and 5| is provided with an adjustable flow plate ll] (see Fig. 3), which is pivotally attached at i s top to the bottom of the partition 2|; and which is adjustable from a position outside the tank 22, by an adjusting rod H, which is threaded at its upper end and provided with an adjusting nut 12, said rod 1| being pivotally attached to an arm 13, formed rigid with the flow plate H1. The flow plate 10 is preferably in the form of a hollow pear in cross-section or in the form of a streamlined body having a generally tear drop configuration in cross-section to provide a streamlined flow of fluid in the U-shaped water column to provide uniform action over substantially the entire lateral dimension of screen 21. It should be understood that the hollow plate 10 is elongated as shown in Fig. 1 as it forms a downward continuation of the partition 26 between the opposing walls of the compartment in which located.

In addition, water is supplied to each individual cell 59 and 5| from a water main 14, by a water control valve 15, provided with an operating shaft 16, operable from the exterior of the tank 22 by a removable hand wheel Tl, there preferably being only one hand wheel I1 for operating the four control valves, there being one said valve 15 for each of the cells 50 and 5|.

Furthermore, associated with each of the cells 50 and 5| is an individual rotary air valve 18, the structure of which is hereinafter described in complete detail and which forms an important feature of the invention. It may be pointed out that the four rotary air valves 18, are driven from a common drive shaft 19 which is driven from an electric motor by an appropriate chain and sprocket driven mechanism 8 It may further be pointed out that the aforementioned elevating conveyors 4| and 43 are also driven from the drive shaft 19' through appropriate chain and sprocket mechanisms 82 and 83 respectively.

As hereinafter described in full detail, the rotary air valves 18 are very flexible, thereby to adjust the type of stroke provided in each cell 50 and 5| of the jig. To provide for ready access to these control valves 18 and to the adjusting means for the water valves 15 and flow plates 10, I provide a walk 84, which extends longitudinally along the top of the jig adjacent to which are spaced handrails 85 and 86 between which extends a transverse walk 81 having a handrail 88 adjacent each side. It may additionally be pointed out that extending longitudinally throughout tank 22 is a pair of reenforcing pipes 89 which are attached to all of the transversely extending partitions or walls.

Attention is now directed particularly to Figs. 1 and 4 to 12 inclusive of the drawings, which illustrate the detailed structure of each of the rotary air valves 18 and. the adjustable cycle of operation provided for each cell thereby,

Each of said rotary air valves 18 comprises a casing 90, preferably in the form of a casing which has a generally cylindrical shaped portion 9| and at one end has a head carrying a journal bearing 92, which supports the driven shaft I9, said journal bearing 92 being provided with an appropriate grease fitting 93. From said head end of the casing 99 there projects a downwardly extending integrally formed air inlet conduit 94, which communicates with the interior of said casing 99 by way of air inlet port 95. As may be seen by reference to Figs. 1, 4 and 9 of the drawings, the conduit 99 is slidably received by a short pipe 96, which extends into and has open communication with the aforedescribed plenum chamber 3|. An air-proof packing gland in the form of a tubular rubber ring 91 is attached to the inlet conduit 94 and presses against the interior walls of the pipe 96 to provide a fluid-tight sliding connection. It is evident particularly, by reference to Fig. 9 of the drawings, that an air inlet passageway is provided from the interior of the plenum. chamber 3| to the interior of the casing 90 of the rotary air valve I8 by way of pipe 99, conduit 99 and air inlet port 95, which passageway is open at all times.

The casing 99 is also provided with an integral downwardly extending main air passage conduit 98 which extends into a downwardly extending pipe 99 which, as clearly seen by reference to Figs. 1 and 3 of the drawings, extends entirely through the plenum chamber 3| and has its bottom opening into the air chamber 29. There is a packing gland I 99, similar to the aforedescribed packing gland 91, which is attached to the conduit 98 and makes a sliding air-tight connection with the pipe 99. By reference particularly to Fig. 9 of the drawings it will be seen that at the top of the conduit 98 there is a central web I 9I, which forms an inlet port I92 in the top of the conduit 98 and an exhaust port 593 in the top thereof.

The circumferential portion of the complete circle of the cylinder 9I which is subtended by the ports I92 and I93, as illustrated in Fig. 9 of the drawings, is a matter of considerable importance; that is, each of the ports I92 and I93 substends a portion of the arc of a circle which describes the interior of the cylinder 9!. In the valve here described, there is an angle of 110 degrees of the 369 degrees representing the complete circle. It is to be distinctly understood,

however, that this angle may be made anything desired up to the theoretically maximum value of 180 degrees; and as hereinafter described, the effective size of this opening in degrees is adjustable between zero and the maximum provided by the structure which, in the illustrated case is r 119 degrees. As previously mentioned, the ports I92 and I93 both subtend angles of 110 degrees, although if desired they may be made to subtend the maximum angle or any other desired angle.

Associated with the inlet port I 92 is an adjustable damper I94, which may be adjusted to vary the effective size of opening thereof and a similar damper I95 is provided in association with the exhaust port I93. These dampers I94 and I95 are of similar construction except that their control mechanisms are on opposite sides of the conduit 98, as clearly illustrated in Fig. 8 of the drawings.

The damper I95 will be described in detail and it is to be understood that the description also applies to the damper I94, except for the revision above mentioned.

Said damper I95 comprises an arcuate valve member I99 which is pivotally attached to opposite walls of the conduit 99 by a pivot bolt I9!- which extends free y through one wallof said conduit 99 and is threaded to a boss I98 formed on an arm I99, both of which are integral with said valve member I99, as shown in Fig. 6.

At the opposite end, valve member I96 is provided with an arm II9 carrying a boss III (Fig. 6) which is keyed to; a pivot shaft II2 which is journaled in the opposite wall of conduit 98 and is keyed to an operating handle II3 carrying an integral pointer H4 in the form of a segment of a disc having an elongated slot II5 therein through which extends a clamp screw H9. Pointer H4 is associated with a scale I I! carried on the exterior of the conduit 98 which indicates the percentage of maximum opening provided by the position of the damper I in any position to which it is adjusted. The screw II6 of course provides for locking said damper I95 in any position to which it is adjusted.

To support the complete rotary air valve I9 in position, it is to be noted that extending transversely of the top plate 32 of the plenum chamber 3| is a pair of spaced upright supports H9 (see Figs. 4, 8 and 9') provided with appropriate bolt holes through which extend four bolts II9 adapted to be attached to four brackets I29, two of which are formed integral with the conduit 94 and two of which are formed integral with the conduit 98. The brackets I 29 are provided with elongated horizontally extending slots I2I (see Fig. 8) which receive the bolts H9 and thus provide for lateral adjustment of the valve 18 with respect to the pipes 99 and 99. Vertical adjustment of the rotary air valve 18 with respect to pipes 96 and 99 is provided by set screws I22, of which there is one associated with each of the brackets I29, which are adapted to bear on the tops of the plates H8. This of course provides for ready adjustment both vertically and laterally of opposite ends of the rotary air valve I8.

As was above pointed out, as seen by reference to Fig. 8 of the drawings, the inlet port I92 and the exhaust port I93 subtend arcs which in the particular valve illustrated are equal to degrees. The efiective size of each of these ports is preferably adjustable from zero to the maximum value of 110 degrees, and to provide for this adjustment, together with indicating means, the cylindrical portion 9I of the casing 99 is provided with two pairs of adjustable arcuate slide valves or slide plates, one of each pair being on opposite sides thereof, which, as seen by reference to Fig. 7 of the drawings, are designated generally by the letters A, B, C and D. The slide valves A and B are associated with the inlet port I92 and control its effective size, and the slide valves C and D are associated with the exhaust port I93 and control its effective size.

By referring particularly to Figs. 8 and 9 of the drawings it will be seen that the slide valve A comprises an arcuate plate I23 which fits in an arcuate groove I24 (see Fig. 9) formed in the interior of the cylinder 9|. Plate I23 extends over an arc of approximately 80 degrees. The adjustable slide valve B is of similar construction and generally oppositely positioned with respect to slide valve A and it comprises an arcuate plate I 25 which fits in the arcuate groove I24 formed in the interior of the cylinder 9|. Plate I25 extends over an arc of approximately degrees.

As clearly seen by reference to Figs. 8, 10 and 11 of the drawings, approximately midway of the arc of the plate I25there is an operating handle I29 which is rigidly attached thereto by screws I21, and which is adapted to slide in an elongated arcuate slot I28 formed in the cylinder 9|. Adjacent the lateral edges of the slot I28 said cylinder 9| is embossed as seen at I29 (see Fig, 11). Adjacent one side of the slot I23 is an indicating scale I30. A combination pointer and clamping member I3I extends through a transverse notch in the handle I26 and has a point adjacent the scale I30. The handle I26 is clamped in any position to which it is adjusted by the cooperation of the clamp member I3I and a set screw I32 threaded in the handle I 26 and extending loosely into a receiving pocket in said clamp member I3I. It is evident that by screwing down the set screw I32 the'plate I25 will be clamped in adjusted position by the bearing of the clamp member I3I on the embossment I29.

It may be stated that a structure similar to that above described in connection with slide valve B is also provided in connection with each of the slide valves A, C and D. However, it is to be noted, as above pointed out, that the arcuate plate I23 associated with the valve A extends only over an arc of 80 degrees and the handle associated therewith is preferably attached to the topmost portion of said plate I23, as illustrated in Fig. 8 of the drawings. The slide valve C is identical in structure to the slide valve A and the slide valve-D is identical in structure to the slide valve B.

By reference to Fig. 8 of the drawings the importance of the positions of the slide plates I23 and I25 will be evident. As was above pointed out, the arcuate extent of the inlet port I02 is 110 degrees. degrees and the extent of the plate I23 is 80 degrees. This of course makes a total of 360 degrees and thus permits the two plates I23 and I25 to be adjusted alternately. When the upper ends are in contacting relation the inlet port I02 is in its wide open position. If the inlet port I02 extends over an angle in excess of 110 degrees an appropriate reduction must be made in the arouate extent of the plate I23 or of the plate I25.

It is also evident of course from reference to Fig. 8 of the drawings that by adjusting the slide valves A and B the lower edges of the plates I23 and I25 may be brought toward each other thereby providing for an adjustable variation in the effective size of inlet port I02 from the maximum value, which is 110 degrees in the illustrated embodiment of the invention, to a minimum value of substantially zero. This of course makes for a very flexible adjustment of the effective size of the inlet port I02. 7

As was above pointed'out, a similar structure is provided in association with the exhaust port I03, provided by the two slide valves C and D, which make for the same range of adjustment as above described.

It may be pointed out that the rotary air valves 78 are normally adjusted in operation so as to carry out the method of jigging described in the patent to Byron M. Bird, No. 2,132,376 dated tober 11, 1938 for a method of jigging. As there pointed out, the jigging cycle includes four periods of air control comprising the air inlet period, during which air flows into the chamber 29, an expansion period during which the chamber 29 is sealed and the air therein expands, an exhaust period, during which the air is free to flow from the chamber 29 to atmosphere, and a compression period during which the air in chamber 29 is again sealed and compressed by The extent of the plate I is 1'70 the upward movement of the jigging liquid into said chamber 20.

To provide these four cycles of operation each rotary air valve I3 also includes a rotor I33 which i has an outer cylindrical surface I34 which rotates in the aforementioned cylinder 9I and which is provided with a central radially extending partition I35, which divides the cylinder I34 into two compartments, said partition I35 being provided with an integral hub I36 which is keyed to the shaft I9 and provided with a key retaining set screw I31. The partition I35 divides the rotor into an air inlet control portion I38, seen at the right hand side of the partition in Fig. 9 of the drawings, and an air outlet control portion I39, seen at the left of said partition I35. In addition, the rotor I33 includes radial webs I40 which extend from the hub I36 to the cylinder I34. The air inlet control portion I38 of the rotor I33 is provided with an air inlet control port I4I which may subtend an arc of any desired size, and in the illustrated embodiment of the invention this are is approximately '70 degrees. The air outlet control portion I39 of the rotor I33 is also provided with an air outlet control port I42 which is preferably of the same circumferential extent as the port MI. The center lines of the arcuate ports MI and I42 are preferably 180 degrees apart, or in other words,

'are diametrically opposite, as clearly illustrated by Figs. 8 and 9 of the drawirms.

To illustrate one representative cycle of operation of one cell of the jig under the control of one of the rotary air valves IS attention is now directed to Fig. 12 of the drawings. The cycle of operation there represented is one in which all of the adjustable arcuate slide valves A, B, C and D are set with their pointers to read 45 degrees on the aforesaid scales I30. Assuming the rotor I33 to be rotating in a clockwise direction, as indicated by the arrow I43, in Figs. 8 and 12, it will be seen that an air inlet period of degrees is provided between the characters A and B which may represent diagrammatically the handles A and B. In other words, the slide valves A and B are adjusted so that the sum of the two readings on the scales I30, associated with them is equal to 90 degrees, and in the illustration given each is set at 15 degrees.

It may be stated that under these conditions the effective size of the inlet port I02 is reduced from the maximum value of degrees to 20 degrees, whereby the air inlet period will be equal to the size of air inlet control port MI in degrees, which is 70, plus the effective size of air inlet port I02, which is 20, making a total of 90 degrees. This is because of the fact that the air inlet period will begin as soon as the forward edge of air inlet control port I II clears the forward edge of the the plate I23 in the direction of rotation of said rotor I33, whereby compressed air will flow from the plenum chamber 3I (see Fig. 9) by way of pipe 99, conduit 94, air inlet 95, open end of rotor I33, air inlet control port I4I, inlet port I02, conduit 98 and pipe-99 into the air chamber 29, as indicated by the arrows I44. When the trailing edge of the air inlet port It! has overlapped the bottom edge of the plate I25 the expansion period will begin and this will continue until the leading edge of the air outlet control port I42 clears the lower or leading edge of the plate of valve 0 similar to the plate I23 of valve A, which of courseterminates the expansion period and starts the exhaust period during which air in the chamber 29 will flow over the obvious path indicated by the arrows I45 (Fig. 9 of the drawings) to atmosphere. The exhaust period ends and the compression period starts when the trailing edge of It is evident that the reference characters A, r

B, C, and D on Fig. 12' of the drawings may represent the slide valves A, B, C, and D. It is thus evident that by adjusting any one or more of said slide valves A, B, C and D, the sizes of the inlet, expansion, eXhaust and compression periods.

may be adjusted, and due to the fact that any one of the radial lines A, B, C and D of Fig. 12 may be adjusted in a clockwise or a counterclockwise direction, an extremely flexible control valve is provided so that the relative portions of as:

complete cycle, as represented by inlet, expansion, exhaust and compression periods may be widely adjusted.

It is to be particularly noted that one of the important features of the control valves of the;

jig of the invention is that the expansion and compression periods do not have to be the same, as they do in the valve described in the aforementioned Bird patent. As a matter of fact, the only limitations as to the sizes of the various periods is as follows:

With the valve above described the minimum value of inlet and exhaust periods is 70 degrees and thisis because the size of the air inlet control port MI is 70 degrees. If the size of the air inlet port MI is other than 70 degrees, the minimum inlet and exhaust periods will vary accordingly. Another limitation is that the maximum value of the air inlet and air exhaust periods is 180 degrees and this is because the sum of the.

angles subtended by ports MI and I42 on the one hand and the angles of the inlet and exhaust ports I82 and I63 on the other hand is 180 degrees. In other words, air inlet port I I is 70 degrees and inlet port I02 is 110 degrees and the sum is 180 degrees. Likewise, air outlet port I42 is '70 degrees and exhaust port IE3 is 110 degrees, and the sum is also 180 degrees. Any adjustment in any of these ports provides a corresponding variation of this maximum value.

Furthermore, it is to be clearly understood that no two of the four periods of inlet, expansion, exhaust and compression need be of the same value, and furthermore, the phase relation between them can be widely adjusted.

It may be pointed out that to determine the value of the inlet periods the scale readings associated with valves A and B are added together. To determine the value of the exhaust periods the readings of the scales associated with valves C.

and D are added together. To determine the expansion period the readings of the scales associated with valves B and C are added together and this total is subtracted from 180. To determine the compression period the readings of the scales associated with valves D and A are added together and this total is subtracted from 180.

It may be noted, by reference particularly to Fig. 4 of the drawings, that between the readings 3G and 48 on scales I30 is a center line marking and whenever the pointer I3I is at this position the bottom edge of the associated plate I23 or I25 is at a position directly below the axis of shaft 79. It i thus evident, of course, that if any two cooperating valves, such as valves A and" B are both placed at this center line position, the associated inlet or exhaust port, such as inlet port I02, will be substantially completely closed and, of course, this condition should be avoided. It is also evident that it is impossible to place two cooperating valves with their indicators both below this center line position because this would require an impossible overlapping of the plates I23 and I25, or their equivalents. It i furthermore to be noted that not only is it possible to adjust the slide valves A, B, C and D to obtain variable amounts of inlet, expansion, exhaust and compression periods but it is also possible to eliminate entirely the compression and expansion periods, thus retaining only inlet and exhaust periods.

It may also be noted, as seen in Fig. 9, that an air sealing gland is provided by washer I and compression ring I M attached to rotor I33 by counter-sunk screws. Lubrication fittings I53 are also carried by cylinder 9! for lubricating rotor I33.

In the operation of the jig, the raw coal to be treated to remove the impurities therefrom, is fed over the feed chute 35 to the compartment 33. In the operation of the jig there are two types of water flow which are controlled. Water pulsations, forming the jig stroke under the control of a rotary valve it should act uniformly on all parts of the bed of material to be treated. In order to average out to a smooth uniform pulsation by eliminating abnormal disturbances at one point in the bed, and dead spots at other points therein, each compartment 33 and 34 is divided into two cells a illustrated at 5| and 5| in Fig. 1. For each cell is provided a controlling valve I8, and each cell is also provided with an adjustable fiow plate IE5 at the bottom of the central partition, under which the water moves from the pulsion to the screen compartments. The adjustment of this flow plate Ill diverts the water to diiferent parts of the screen compartment, as may be required for uniform action. Furthermore, each rotary valve I8 is provided with means for adjusting each period of expansion, exhaust and compression, and therefore the expansion and compression may be adjusted for different periods.

It will therefore be seen that in each of the cells the successive periods of air inlet, expansion, exhaust and compression successively follow during which compressed air is successively allowed to flow into the chamber 29 and cause an upward movement of liquid through the screen 27 which continues during the expansion period, whereupon the chamber 29 is sealed and the compressed air therein expands to effect a pulsation to move the liquid through the screen 21 to the dotted line position at I55 in Fig. 3. By referring to Fig. 9 it will be seen that the arrows Hi4 indicate the passage of the compressed air through the port I M into the chamber I 29, as illustrated in Fig. 3. When the shaft I9 is rotated to out off the port I lI from the conduit 98, the compressed air is sealed in the chamber 29.

On further rotation of the shaft 79 of Fig. 9, the port I42 communicates with the conduit 98 and thereupon the air is exhausted from the compressed by the water flowing downwardly through the screen 21. The same general cycle of operation takes place in each cell of each of the compartments 33 and 34 but it should be particularly noted that each cell is provided with expansion and compression adjusted for different periods, the upward or pulsion movement of the water through the screen 21 first causes the top of the bed to expand which is immediately followed by expansion of the entire bed so that settlement starts from the bottom of the expanded bed and enables the refuse to immediately settle to the bottom. In other words, with the differential stroke or the expansion and compression adjusted for different periods, the entire bed is opened up by the upward pulsion movement, and stratification is free to take place throughout the entire expanded bed of material. Consequently during the expansion period the heaviest particles, having settled to the bottom or directly on the screen, will prevent the fines from reaching the screen and passing through the same into the hutch. Without the differential stroke or difference in the expansion and compression periods, the upward or pulsicn stroke: tends to lift the bed en masse and settling takes place only from the bottom of the bed and this permits the finer pieces to work down closer to the screen openings with the result that the hutch product as well as the tendency to clog the screen are increased. Fur thermore the effect of a jig bed without the dif ferential stroke is to leave the top layer still tight and with the heavy impurities still imbedded therein even after compression occurs.

Circulation water, pumped to the jig and passing through it, forms the conveying element in the jig. This flowing water moves the coal from one compartment 33 to the next compartment 34 and thence to the outlet chute 38. Adjustment of this incoming water also affects the jig pulsations and is obtained by the valves I one of which is provided for each of the cells.

The adjustments effected at A, B, C, D, Fig. 7; enable utilization of different velocities of water movement during the various phases of the jig stroke for each cell. These differential velocities are under the operators control. The potential problems of coal size, volume and washability are met by making such adjustments. Adjustments of expansion and compression for different pe riods or providing the controlled differential stroke, enables the jig to initially open the jig bed from the top instead of the bottom, permitting deeper beds and higher capacities. In other words, by independently adjusting the expansion and independently adjusting the compression, each may be widely varied to suit con-l ditions of operation on the material being treated, thus increasing the efficiency of operation.

It should also be noted that by having the coal and refuse in both compartments move in the same direction toward their respective refuse ejectors, assures a more uniform separation of the fine materials. The smooth, rhythmic action secured by independently controlled successive cells, is not disturbed by eddies because the coal and refuse in both compartments move in the same direction toward their respective outlets. Furthermore, the parallel flow inboth compartments facilitates settling of the refuse quickly so as to freely move toward the refuse outlet. The movement of the settled refuse toward the outlet is assisted by the forward movement of the material above it. The forward movement of the refuse is also assisted and controlled by adjusting the slope of each screen plate by means of the adjustable hang rod 53 as shown in Fig. l.

Overlapping connections between the bottom of each screen and the upper edges of the walls of the cells confines the upward pulsation of the water when passing through the screen. The screen plates may be set in each compartment at the slope best suited to the type of refuse. In order to operate a jig at maximum effective capacity, a uniform refuse bed should be maintained. Not only are the slopes of the screen plates adjusted but the float operated automatic refuse discharge mechanism 46 must also be adjusted so that the refuse is drawn off at the same rate as it accumulates on the jig. The electric motor 48 may operate at constant speed to reciprocate the rod which is connected to the pawls of the pawl and ratchet mechanisms provided to rotate step-by-step the rotary ejectors 45. The float control mechanism determines the number of teeth on the ratchets to be engaged by the actuating pawls and therefore automatically controls the extent to which the rotary ejectors are moved at each step. The greater the rate of refuse accumulation, the faster becomes its rate of removal because the float rises and increases the rotations of the ejectors.

Each perforated plate or screen 21 is provided with a plurality of reinforcing bars 28 on the bottom thereof to minimize breathing or bending movements of the screen plate. It is desirable to maintain the upper surface of each screen plate perfectly flat as such breathing would tend to throw the refuse up into the coal strata. Furthermore, the upper surfaces of the screen plates are smooth and unobstructed to assure free sliding of the refuse over the same to the ejectors.

Each ejector may be provided with an apron I56 having the shape shown in Fig. l, and this apron is pivoted at I51 to the weir or channel beam 31 and provided with a weight I58 so as to hold the plate yieldingly against the rotor of the ejector 45. The swinging apron I58 prevents damage to the ejector by permitting oversized pieces of waste material to pass over the rotor.

It should also be noted that by means of the set screws I22 each rotary air valve 18 may be tilted for co-operation with the bolts H9 along the slots I2I to secure alinement of the four rotary air valves I8 since they are all connected .for rotation to the same shaft 19.

It is, of course, evident that the valves I8 may not only be individually adjusted to determine the relative periods of inlet, exhaust, expansion and compression, but also the control provided by the dampers I84 and I05 provides for a further controlling of the action of said valves and this extremely flexible control makes possible a wide variation in the shape of the time-velocity curve of water movement to provide the desired jigging action. This jigging action, of course, is effective to stratify the bed of material on the screen 2! with the high gravity refuse such as pyrite and shale in the bottom stratum, above which will be the intermediate gravity material such as bony coal and possibly some shale.

The refuse ejecting mechanism 45 and float operated refuse discharge mechanism 46 cooperate to maintain a substantially constant bed depth of high gravity refuse on the screen 21 of compartment 33 as it is formed, by ejecting said high gravity refuse substantially at the rate it forms. The ejected refuse is received in the boot of elevator casing 42 from which it is elevated and discharged by elevator 43. The clean coal together with intermediate gravity refuse will pass over the weir 36 of compartment 33 with water, which may have an average level along the line I55, into the compartment 34 where it is supported on screen 21 and subjected to further jigging action with the ultimate discharge of the refuse into the boot of casing 40 by way of opening 414, with the clean coal, and of course some water, flowing over the adjustable weir plate 5'! and down the chute 38 to the receiving sluiceway. All the while this jigging action is taking place an adjustable amount of water is being fed to each cell 5%) and 5| of each compartment 33 and 34 and the flow plates 1!! of each cell are adjusted to the position at which they give best results.

It may be pointed out that in general the treatment to be given the material in compartment 34 is different from that desired in compartment 33 due to the difierence in the specific gravity of refuse which is to be removed and consequently there will be a different valve setting for the valves 18 associated with the compartment SE from that of the valves 18 associated with the compartment 33. It is also evident that this adjustment may be provided for the twovalves 78 associated with the cells 50 and 5| of compartment 34.

It will therefore be evident that I have provided a jig which is unusually flexible and which can provide any desired shape of time-velocity curve of water movement through the several material supporting screens, to effect the most eflicient treating action on the material introduced. The time-velocity curve can be readily adjusted even while the jig is in operation, making it possibl for the operator to adjust the jig and test the results so that the most efficient treatment is given to the particular material being treated, it being well known that various materials such as coal found in different mines and in different parts of the country require different treatments to effect an eificient separation of the refuse from the clean coal.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In a jig, the combination with a jigging liquid receiving container, of a material supporting screen therein, an air chamber, mechanism for supplying air cyclically to said air chamber to force liquid through said screen cyclically, said mechanism including a cyclically operated valve constructed to have air inlet, expansion, exhaust and compression periods during each cycle of operation totalling 360 degrees, and including means for adjusting the number of degrees of each period while the valve is operating, said means being constructed and arranged to have such flexibility that the expansion and compression periods may be adjusted for different periods.

2. In a jig, the combination with a jigging liquid receiving container having two compartments, of two material supporting screens one in each compartment, a. weir between said compartments, two refuse ejector devices one for each compartment, two pairs of cells one pair associated with each screen and each cell adapted to contain a U-shaped column of liquid with one end under a, screen and the other end extending to an air chamber, a plurality of valve structures one for each cell to control the supply of compressed air cyclically to said air chambers to force liquid through said screens, each valve structure including means to adjust the periods of expansion and compression during operation to be relatively different when measured in degrees for each cycle of 360 degrees, means for directing a flow of liquid and material to be cleaned through said compartments over said screens and weir, mechanism for operating said valve structures during such flow to secure rhythmic action of the jig pulsations for the purpose of settling the impurities for flow to said ejector devices and the floating of the coal over said weir from one compartment to the other, and mechanism comprising floats above the screens one in each compartment for regulating the operation of said ejector devices.

3. In a jig, the combination with a U-shaped jigging liquid receiving container, of a material supporting screen in one leg of said container, an air chamber at the upper end of the other leg of said container, means comprising rotary valve mechanism for supplying air cyclically to said air chamber for a U-shaped column of liquid through said screen cyclically, said rotary valve mechanism having an air inlet from a source of compressed air and means for effecting inlet, expansion, exhaust and compression periods totaling 360 degreesin the aforesaid air chamber during each rotation of the valve mechanism, and adjustment means on the valve mechanism operable while the valve mechanism is rotating including means to secure such flexibility of the jigging operation on the bed of material supported by said screen that the expansion and compression periods may differ from each other in the number of degrees during each cycle.

ORVAL R. S'I'RAlVN. 

